The present invention relates to a heat exchanger of the semi-modular type for a nuclear reactor and more particularly a fast neutron reactor cooled by a liquid metal and of the integrated type.
To provide a better understanding of the invention, FIG. 1 shows an integrated reactor in a vertical sectional view. It is possible to see in per se known manner a concrete block 2, whose upper part is sealed by the slab 4. The main vessel 6 containing the complete primary circuit is suspended on said slab 4 and is duplicated by a safety vessel 8.
Within the main vessel 6 there is an inner vessel 10 supported by a flooring 12 resting on the main vessel. The inner vessel separates on the one hand the hot liquid metal, generally sodium leaving the core 16 supported by the flooring and on the other hand the cold metal contained in the annular space 18 between the main vessel 6 and the inner vessel 10. In this type of reactor, the hot sodium leaving the core is taken up by pipes 19 which introduce the hot sodium leaving the core into intermediate exchangers 20. Pumps 22, also located in annular space 18 ensure the circulation of the primary fluid by reinjecting the liquid metal at the base of the core into support 14 by means of pipes 22b.
Nuclear reactors of this type using intermediate heat exchangers of the modular type are known. For example, reference is made to French Patent Application 77 08384 filed on Mar. 21, 1977 in the name of the present Applicant for an "annular heat exchanger" and the application for a certificate of addition EN 77 21451 filed on July 12, 1977 by the Applicant for an "annular heat exchanger".